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A review of the forest models developed and applied by Timberlands West Coast Ltd (TWCL) and Landcare Research Ltd (LRL) has been carried out. The models were reviewed on the basis of default settings for red beech in the Maruia Working Circle. After identifying the similarities and differences between the two models, a sensitivity analysis was carried out to quantify the impact of any differences on model outputs, in particular stand structure and harvest yield. A sequence of model variants was developed and run, starting with the TWCL default model and ending with the LRL default model. Each variant in the sequence differed in only one factor, thereby allowing quantification of the relative sensitivity of model outputs to that factor. The review focuses on the impact of differences between the models in terms of mathematical formulation, input data and assumptions. However, it excludes any analysis of the appropriateness and relative merit of the different mathematical formulations, input data and underlying assumptions. Although these are important considerations they are beyond the scope of this review. Both models can be categorised as Stand Class Models and use the Stand Table Projection Method to project the growth of a stand by simulating the growth of classes of trees. This is a commonly used approach for modelling, particularly for uneven-aged forests. The differences in mathematical formulation between the LRL model and the TWC model are: 1. Mortality is included in the transition coefficients in the LRL model whereas it is treated as an absolute reduction in the TWCL model. 2. The transition coefficients have a different structure because of different assumptions about the distribution of trees within a size class and the residence time of trees in each class. Incorporating mortality within the transition coefficients rather than as an absolute reduction has a minimal impact on model outputs. The use of LRL transition coefficients, without any other model changes, has a major impact on model outputs. However, once mortality is adjusted to reflect the different coefficients, model outputs for the LRL approach are similar to model outputs for the TWCL approach. Another difference between the models is that the LRL model allows for compensatory growth (Version 1.1) and mortality (Version 2). The model includes functions which allow tree growth rates and mortality to vary in response to changes in stand basal area. Invoking these functions can have a major impact on model outputs. Both models have the same initial tree size distribution. There are minor differences between the tree growth rates and the recruitment rates specified in the two models. These differences have a negligible impact on model outputs. The models (in terms of default settings) differ in the relationship between harvest and mortality. A fundamental assumption of the TWCL model "is that mortality is subsumed into harvest through the careful selection for harvest of trees already prone to direct mortality or mortality by association with dying or falling trees". In contrast, an underlying assumption of the LRL model is that "logging imposes mortality that is largely additional to natural mortality in any one year". These differences have a major impact on model output.

The report comprises four Parts. Part 1 presents an overview of risk analysis and its general application to the management of New Zealand's indigenous fauna and sets out a framework for risk analysis for indigenous fauna with reference to the example analysis for indigenous parrots in Part 3 of the report. Part 2 lists the indigenous vertebrate fauna populations of interest and considers, in general terms, the range of disease agents that need to be covered. A semi-quantitative method for prioritising each population of interest so as to allow an orderly progression of successive risk analyses based on each population's priority ranking is presented. Part 3 is an example evaluation of risk analysis for managing the threat of exotic disease to indigenous parrots (psittacines). Part 4 recommends the use of risk analysis as a standard and appropriate tool for the management of risk of exotic disease to indigenous fauna in New Zealand. The report recommends a number of actions that the Department of Conservation could make to reduce risk of exotic disease to indigenous psittacines in particular and indigenous fauna in general.

The Tahiti flycatcher (Pomarea nigra) is one of several monarch flycatcher species in the Polynesian genus Pomarea, all of which are threatened. The Tahiti flycatcher is currently known from only the western side of Tahiti where, during the 1998-99 season, at least 24 individuals, including 10 pairs, were located in four valleys (Blanvillain 1999). Although ten nests were protected from rats in 1998-99, only three were successful in fledging young. Two of these young apparently disappeared one week after fledging and the third, two months after fledging (Blanvillain 1999). Concern was raised about the possible predation by common myna (Acridotheres tristis), and/or red-vented bulbul (Pycnonotus cafer) on juveniles. In 1999-2000 the Societe d'Ornithologie de Polynesie (MANU) was granted funding for Tahiti flycatcher conservation by the South Pacific Regional Environment Programme (SPREP). During 13-26 September 1999, RP visited Tahiti to advise and help CB with aspects of the programme. This advisory work was funded by the N.Z. Ornithological Congress Trust Board (ICBP). It builds on work by Gaze & Blanvillain (1998) funded by the Pacific Development and Conservation Trust.

The Department of Conservation has assisted the Cook Islands Conservation/Environment Service, and more recently the Takitumu Conservation Area Project, to plan and implement a recovery programme for the endangered endemic forest bird, the kakerori.

There are five toxicants (brodifacoum, bromadialone, coumatetralyl, diphacinone, and flocoumafen) registered for rodent control in New Zealand. They are all anticoagulants and are available in water-resistant bait formulations (i.e. wax coating, wax block, or egg). Several new rodenticide products, which are currently in the process of being developed or registered, including a new anticoagulant difethialone, have also been identified. There are no published data on the relative effectiveness, palatability, or durability of the existing rodenticides for field use under New Zealand conditions. However, relevant published information on laboratory and wild rodents is reviewed. It is concluded that the highest priority should be to assess the four weather resistant, second-generation anticoagulant products (Pestoff® Rodent block, Talon® 50WB, Contrac®, and Baraki®) for palatability, durability, and effectiveness for an island protection situation. Improvements could then be made to the existing products if required with additives to improve palatability or durability, lures to attract rodents, and repellents for non-target insect, lizard and bird species. Trials of an alternative (e.g. cholecalciferol) to the persistent anticoagulants should also be considered for island protection. The most rodent-attractive bait station which also eliminates bird access needs to be determined for the complete island protection system.

The number of humpback sightings and the number of whales recorded in this study suggest a slow increase over the last 10 years, particularly in the last 4 years. The results of this study may have been influenced by a variety of factors, the most important of which may be inconsistent effort. The results presented in this report are broadly consistent with that described by Dawbin (1956). As reported by Dawbin (1956), and found in this study, the northern migration occurs between May and August while the southern occurs from September to December. There is little evidence of a change in migration patterns past the New Zealand coast. The inability to quantify effort is a major limitation with the data and does not make it possible to draw clear conclusions on population size or trends in migration. However, the results are useful in determining the locality and seasonality of humpback whales as they migrate along New Zealand coasts.